why dont they just have a pitstop window of 5 laps in the middle of the grand prix?
then they dont have to shorten the race, and they dont have to make the fuel tank larger either.
so the probability of two people sharing the same birthday in a group of 57 randomly selected people is:
1 - 1*364/365*363/365*362/365*361/365 ... 309/365 = 0.99